Potassium argon dating formula sedating cats on airplanes

The half-live of potassium-40 is approximately 1.26 billion years (that is, 1.26x10 years).

Obviously, this formula depends on the laws of physics remaining constant over time.

The calcium-potassium age method is seldom used, however, because of the great abundance of nonradiogenic calcium in minerals or rocks, which masks the presence of radiogenic calcium.

On the other hand, the abundance of argon in the is relatively small because of its escape to the atmosphere during processes associated with volcanism.

Potassium-argon dating is a method for estimating the age of volcanic rocks by measuring the ratio of potassium-40 to argon-40 present.

The method is based on the fact that the potassium-40 isotope of potassium decays over time to form argon-40.

Archaeologists and biologists are also sometimes able to use potassium-argon dating to measure the age of artifacts and fossils, when these have become trapped in or buried under volcanic rock.

The mathematical formula that is used to figure the age of the rock depends on the half-life of potassium-40 (the time it takes for half the potassium-40 in a given sample to decay).But consider what happens if the argon came from deep within the Earth, where it was formed by Ar ratio as is found in the atmosphere, and the formula that corrects for atmospheric carbon will not correct for this.Finally, we must consider the possibility of argon loss.method is based upon the decay of radioactive potassium-40 to radioactive argon-40 in minerals and rocks; potassium-40 also decays to calcium-40.Thus, the ratio of argon-40 and potassium-40 and radiogenic calcium-40 to potassium-40 in a mineral or rock is a measure of the age of the sample.If the rate of radioactive decay has changed over time, the formula will not give correct dates.